Unanswered: ExtJS 4.1.1 and what version JSBuilder 2 or 3 to used?

Unanswered: ExtJS 4.1.1 and what version JSBuilder 2 or 3 to used?

hi,

I have found version 2 can be downloaded, but no tutorials coming with that. And ExtJs 4.1.1 does not hvae jsbuilder folder, and folder build contains sdk.jsb3 .
So, I am really not sure where to start this. I need to speedup application launch, as it takes ages right now.